Macros queue

Easy. Just put the "Execute Macro" Action at the last Action in each Macro. See the "Execute" Action Category.

Not that I know of. I have dealt with this type of issue by using a series of nested If Then Else Actions, with a Find Image on Screen action with the different buttons in each If Then Else.

Yes, but you will need to get the HTML XPath for the button.
See Click item on Chrome or Safari page by XPath